headers on 98 4.0 engine in a 93-94

[raginred]

im gonna drop a 98 4.0 into a 93-94 4.0 ranger. before i do i want to bolt on a set of headers on the 98 engine. i was told all of the ohv's are the same. if so, should i be able to bolt on a set of headers for a 93-94 on the 98 engine and drop it in? is the reason for there being no headers for the 98+ 4.0s exhaust or emmisions reasons?